diff --git a/web/viewer.js b/web/viewer.js
index db00ef23f..691b7560f 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -627,7 +627,7 @@ var PDFView = {
 
     this.pdfDocument.getData().then(
       function getDataSuccess(data) {
-        var blob = PDFJS.createBlob(data.buffer, 'application/pdf');
+        var blob = PDFJS.createBlob(data, 'application/pdf');
         downloadManager.download(blob, url, filename);
       },
       noData // Error occurred try downloading with just the url.